Game development jams bring many lines of usually dirty code that power often innovative new implementations of various mechanics and rules. Ludum Dare requires source to be visible but neither code nor art has to be freely licensed.

I believe that the histories of TuxKart/SuperTuxKart, Warzone 2100 and OpenArena show that maintenance can be one of the strengths of the open source game development scene. Having more gamejam-made working prototypes available under “safe” free licenses would enable this community to pick up promising projects and slowly build upon them.

Anyways, one of the games that has more than proper licensing information and is both free, open source code and art is Node Reviver. A short description:

Game mechanics and level designs intersecting with Pac-Man’s PipeWalker’s.